It is often desirable for plants to be watered by automatic self-watering devices that are able to dispense liquid (e.g., water) at a regulated and constant rate over a period of time. This applies to a variety of situations, including that the owner may be too busy to water the plants regularly or that the plants need to be left unattended for an extended period of time, such as when the owner is away from his home or office.
Conventional self-watering devices apply the principle of capillary action or wicking and typically consist of a watering wick, one end of which is immersed in a container filled with liquid and the other end of which is exposed to the area to be watered (i.e., the soil or growing medium). However, as liquid is drawn to the growing medium, the liquid level in the container drops and the wicking height, which is the height that the liquid needs to be lifted up against gravity, increases. As the wicking height progressively increases, the efficiency of the capillary action steadily becomes less efficient, the flow rate diminishes, and wicking eventually ceases. This is a major drawback and presents a limitation in the application of the liquid wick in a self-watering device.
Further, most of these conventional self-watering devices utilize wicking systems that incorporate the wicks within the bodies of the pots containing the plants and the growing media. Such self-watering planters or pots are disadvantaged by the fact that, should the wicks need to be replaced due to clogging or the device need to be serviced, the plants and the growing media may have to be disturbed or even excavated.